Biermann Mini-Statement and Center Build

[Biermann]

Post 5 (10/16)

Well I have found time over the last few weekends to complete the crossovers for the TL's, and with a day off this week, was able to throw together the whole center channel along with its crossover boards el quicko. I never got any response regarding different resistor or capacitor values for the TL version of the monitor XO, but went ahead and made the switchable version so I could have some room to play. Also since I went the diy PCB route, I can swap components quite easily if necessary in the future. I ended up having to create double-decker boards, and had to enlarge the opening so they would clear with a standing air coil inductor. I forgot to grab some photos before I popped them in to finish the speaker wiring, however I will take some when I pull them out to complete the veneer and finish.

I stuffed the TL's with one bag of AcoustaFil each, however it required quite a bit of tufting to get a bag to stretch far enough to fill evenly, and I feel I could still use some additional directly behind the woofer.

Overall, though I have only had a brief few minutes to hear the TL's last weekend, and then the CC this morning, I'm impressed. The sound is very omnipresent, yet detailed. There is of course of details I still need to finish before I can officially listen to them like foam sealing the woofers and mids, along with lining the mid tunnels. Then of course there is the real fun part, sanding and finishing. 8O

TL Switchable XO (as far as I could pull it out w/ the speakers attached)



TL's Built Out



Center Channel XO Boards and Box ready for final wiring.



The Three Amigos. You can see the difference in coloring once the wood has oxidized as seen on the TL's.





Post 4 (9/24)

Well I made time to route the baffle and make the window-brace, along with a jig for the boring dowel hole through the TL divider at 21deg.. I also decided to domino the front and back to the sides to make glue-up and alignment easier. Anyhow, with everything ready to assemble yesterday, I spent a late night gluing up, and luckily everything went together without issue.

This afternoon I had time to un-clamp and flush trim the back and sides. I ended up using a rabbeting bit to flush the MDF portion of the front baffle to the sides leaving a 3/64" overhang on Goncalo so that if I decide to veneer the remainder it will hide the glue edge, and i can flush to the veneer. Next, I finished up by routing the tunnel openings, and I made a quick template on the mill for the crossover cover plate opening, and finished up by routing that opening.

Parts Routed and Ready for Glue-Up



Dominoe'd



Glue-Up 1



Glue-Up 2



Glue-Up 3



Results of Today



Post 3 (9/19)

I swear whenever I get free time to work on a project, something else comes up, and I get side-tracked. Anyhow I had offered to build an plasma stand/ A/V cabnet for a friend so that ended up taking my last weekends these last 2 weeks.

However I had some time yesterday to build jigs and also resaw some Goncalo and MDF so I could glue up my front baffles. Here are some pictures of the progress.

Machining the 1/2 template for the internal brace



Finished preliminary cuts and jigs (3rd jig is for the terminus opening)



Baffle glue-up, the finish planed thickness of the resawn Goncalo ended up being 5/16- so resawed and planed some mdf to meet final 1 1/4" baffle thickness



Wiped some alcohol on one piece to show some of the coloring, however once the wood has oxidized the body will be a deeper orange-red, and the dark patches nearly black




History of Build:

Post 2 (9/3)

I decided to switch my build to the Mini-Statement TL's, though I may go ahead and shoot together the original Mini towers as well to compare sound, since I originally bought the parts for them.


Post 1 (8/25)

Hey there, New to the site

After doing some reading over the weekend I decided to try my hand at building some speakers. Due to size constraints I could not build the full-size Statements, and the shorter sealed version would have had the T/M sweet spot too low. So I have decided on the Mini's and the Center, and have a few questions.

1. On the baffle face of both speakers would I cause any problems if I laminate 1/2" of hardwood (Goncalo Alves) on the 3/4" MDF face in place of 1/2" MDF to reach the 1 1/4" final thickness?

2. Can I sweep back the face of the Center 7 degrees w/o detriment? Again, a placement issue that has my center lower than optimal, I am looking to avoid having to tip the whole speaker.

3. I caught the parts for the Mini's ports, however I missed the Center's, could somebody point me to where the necessary parts are listed, thanks.

4. Has anybody compiled a BOM, or the necessary sqft per thickness, for the foam in these speakers if ordering from FBM or another online source.

5. Last, do I need to use a specific type of wire for the interconnects on the networks and to the individual drivers? Stranded vs. solid, etc.. I have a bunch of 16 and 14ga THHN hook-up wire for building control panels and was wondering if it would be okay for the job.

Thank you for the help, and the great site with detailed projects.

-Cheers

[deewan]

Hey there, New to the site

After doing some reading over the weekend I decided to try my hand at building some speakers. Due to size constraints I could not build the full-size Statements, and the shorter sealed version would have had the T/M sweet spot too low. So I have decided on the Mini's and the Center, and have a few questions.

1. On the baffle face of both speakers would I cause any problems if I laminate 1/2" of hardwood (Goncalo Alves) on the 3/4" MDF face in place of 1/2" MDF to reach the 1 1/4" final thickness?

2. Can I sweep back the face of the Center 7 degrees w/o detriment? Again, a placement issue that has my center lower than optimal, I am looking to avoid having to tip the whole speaker.

3. I caught the parts for the Mini's ports, however I missed the Center's, could somebody point me to where the necessary parts are listed, thanks.

4. Has anybody compiled a BOM, or the necessary sqft per thickness, for the foam in these speakers if ordering from FBM or another online source.

5. Last, do I need to use a specific type of wire for the interconnects on the networks and to the individual drivers? Stranded vs. solid, etc.. I have a bunch of 16 and 14ga THHN hook-up wire for building control panels and was wondering if it would be okay for the job.

Thank you for the help, and the great site with detailed projects.

-Cheers

I'm not a speaker guru, but I'll try to lend a hand.

1. Shoud not be a problem. Just make sure you still give the drivers room to
"breathe" with the 1 1/4 inch thick baffle.

2. I don't know if that would really effect the sound, but one thing you would want to be concerned about is if your main seating distance ever changes. You might end up having to tilt your speaker one way or another. I would build the box to spec and then create a speaker stand that can be tilted.

3. http://www.geocities.com/cc00541/Sta..._BOM121008.pdf

4. Sorry, I don't have that answer

5. I would think that wire would be fine. But again and I not a DIY speaker guru.

[ahaik]

Hey there, New to the site

2. Can I sweep back the face of the Center 7 degrees w/o detriment? Again, a placement issue that has my center lower than optimal, I am looking to avoid having to tip the whole speaker.

Some discussion on center lobing HERE

Or

Scroll down Here to post no 201 by Curt.

[LuncHwagon]

1. I laminated a 1/2" piece of Sapele to my plywood baffle. Make sure you let the hardwood acclimate well before gluing. Expect issues proportional to the humidity variation in your area.

2. Curt basically says its not necessary. If you decide to do it, make sure you compensate for volume changes.

3. see the link above.

4. I ordered foam from the source that Jim recommended. When i opened it up, I thought "Man, that is ALOT of foam"

5. Im using plain-jane 16ga stranded. No shorts. I THINK, those small lengths in the crossovers are so short, no need to use something high priced. internal driver connections get same. Im firmly in the camp that a difference cant be heard with lengths that short.

[Biermann]

Thank you guys for the answers, and the help. I spent a few hours hunting the necessary info down and ordered a LOT of foam from FBM.

Anyhow, Curt posted the new revision of the Statement TL while I was waiting for these additional parts, so I have changed course and am going to build the TL's. Though I may just build both cabinets since I have the additional drivers already for the Mini's and order extra parts to build both crossovers.

Regarding my original questions and your guys' answers:

1) I have some interestingly figured walnut I bought a few years back that I may use, though definitely not as dense as Goncalo. LW, I'm happy to hear people giving proper advice on acclimation here, it can definitely ruin an nice piece if not allowed to do it's thing.

2) I found a post where somebody asked similar and it looks like it already has a upward projection, so I will probably stick with original, or I may go a little nuts and seperate TM from W and see what happens.

3) Found the proper port thanks!

4) Dug through threads and found varying suggestion so I just bought a bunch of foam. Though now with the TL's I don't need any except in the Mid-tunnel, luckily i had bought 2lbs of Stuffing form PE when I ordered the center port.

5) Sounds like I am good to go on the wire, since this is my first build I have no idea what's necessary and what's marketing. I understand the higher end crossover components etc., but I see people selling magic wiring that is quite expensive and had no clue what's necessary. Thanks.


It was good to fire up the saw today and make some dust, I have been too busy to play recently, so it was a welcome change. I got everything roughed for the TL's, tomorrow I 'should' have time to build a jig for the heavy angles on the TL and get the routing done.



Until next time. again thanks for the help

[Biermann]

Well, finally some progress and I took some pictures since I see you guys like them.

[PoorboyMike]

Love that saw and the mill!

[Biermann]

Thanks Mike.

Update to show progress.

2 Questions:

1) I know foam goes inside the mid-tunnel, but is there a radius or bevel on theback edge of the tunnel?

2) (Curt will probably have to answer this one) Is the crossover the same for the Statement Monitor or has it changed for this version? If so is there a diagram for this model ?

Thanks guys.

[Biermann]

Getting there, though I have some more questions.

1) I was wondering if I should line the back or sides in the upper region around the TL woofer with wedge foam a la center channel, or is the fiber fill accomplishing the same thing?

2) Is there any issue with the speaker wire or interconnects proximity to large inductors?

3) How critical is the mass of base for the TL's since it is not part of the port system?

4) How much will the sound suffer if I only put a 5/16" roundover or bevel on the front baffle?

Thanks.

[Curt C]

1) I think the stuffing is sufficient, but there is certainly no reason you can't line the walls as well. Certainly it has the potential to improve things.

2) No

3) It's not, although in some situations the additional mass will ameliorate energy from transmitting into the floor.

4) Likely any perceived difference will be minimal.

C